Nutritional supplements: hit or myth?

There has been a huge increase in public information about how to get all the necessary nutrients from a healthy, balanced diet, yet large numbers of people continue to opt for daily food supplements at a significant cost.

The most recent figures suggest that one-third of women and about one-fifth of men in Ireland regularly take food supplements.

Go into any health food store – or pharmacy or supermarket – and you’ll see shelves brimful with multivitamin and mineral tablets, powdered, dried or juiced concentrated food extracts and various fish oils.

Stores such as Holland & Barrett in Grafton Street, Dublin, say food supplements make up about 70 per cent of their sales. Are these valuable extras that keep our bodies in tip top form or are they a waste of money better spent on good quality food and cooking meals from scratch?

"Most people come in for multivitamins because they are feeling a bit run down at the start of the year," says Aisling Malone, who has completed the Holland & Barrett nutritional training.

“Some people scare themselves by looking up their symptoms online and maybe take something for feeling low in energy without dealing with their sleep problems. We try to talk to customers about their symptoms and advise them on that basis.”

Food importer William Rochford has recently launched True Life Shake Up 50+, a food supplement aimed at those over 50.

“I’m 52 myself and I think it’s important to supplement the diet because [I believe] most people aren’t getting enough protein and calcium from their food.

“A lot of people don’t drink milk anymore and don’t eat a lot of cheese or eggs. I agree that it’s most important to have a good balanced diet but a lot of people don’t get enough nutrients from their food,” says Rochford.

National survey
The national adult nutrition survey from 2011 found that most vitamin and mineral intake among adults was adequate. However, the large-scale study pointed to significant inadequate intakes of vitamin A and calcium in 18-64 year olds and low vitamin D intakes in the general population.

The survey also found that food supplements contributed to about 9 per cent of the vitamin and mineral intake of the population. In other words, on average, people are getting almost 10 per cent of their vitamins and minerals from supplements.

It also found that adults aged over 65 showed a significant lack of vitamin A, C, B2, folate and calcium as well as vitamin D. Women of reproductive age had low iron levels and weren’t taking the recommended daily supplement of folic acid for the prevention of neural tube defects in babies.

A national initiative to recommend vitamin D supplements for babies up to the age of one was implemented in 2007.

Apart from this and the continued recommendation for women of child-bearing years to take folic acid supplements for three months before and during the first three months of pregnancy, there are no national recommendations for the taking of food supplements.

In fact, Prof Mary Flynn, chief specialist in public health nutrition at Food Safety
Authority of Ireland, is more concerned that people might suffer from adverse reactions by taking too many vitamins and minerals from several sources than having inadequate levels.

EU safe levels
"The EU has not set maximum safe levels for vitamins and minerals. All we have are tolerable upper levels. What concerns me more – especially among the better off in our society – is that people are getting too many vitamins and minerals from a combination of food supplements and fortified foods such as milk and spreads," says Foley.

“What raises our concerns are the high-dose vitamin and mineral supplements on the market because of the lack of safe maximum levels.”

Since the EU food supplements directive was transposed into Irish law in 2007, the FSAI must be notified about any new nutritional supplements that come on the market.

Maximum levels
However, because safe maximum levels have not yet been set at European level, the FSAI doesn't have the legal authority to take any product off the market. If it has serious concerns, it will refer a high-dose supplement to the Irish Medicines Board.

Foley says some food supplements on the market have 10 times the recommended daily allowances (RDA) of specific vitamins and minerals. Each product must state the RDA percentage of each vitamin or mineral it contains; however, it’s up to consumers to decide whether this represents a risk for them or not.

Foley is not concerned about the adverse effects of vitamin and mineral supplements if they are taken at the RDA levels, but says the problem is that with some fat soluble vitamins,excess fat soluble vitamins A, D, E and K are stored in the body while excess water soluble vitamins C and B complex are excreted in the urine.

Flynn cautions overuse of vitamins and minerals by citing studies such as the famous Caret (beta-carotene and retinol efficacy trial) study.

In this 1996 study, smokers were given beta-carotene to prevent cancers but the study had to be stopped early because of an increase in lung cancer and deaths among those taking the supplement.

She also cautions people from taking iron supplements for general tiredness without first checking with their GP if they have haemochromatosis, the genetic condition that stores excess levels of iron in the body with serious damage to internal organs, which is common in Ireland.

Nutritional therapists
However, in spite of this official cautionary approach to the use of high-dose supplements, there are nutritional therapists who encourage their clients to seek out nutritional supplements with levels above the RDAs.

Anna Collins says she widely recommends food supplements – particularly multivitamin supplements – to her clients alongside efforts to improve their diet.

“The RDAs were set 40-50 years ago and are out of date now. The RDAs were set at levels to prevent serious deficiencies, not to give optimum health.

“And we need higher levels of nutrition now because of our stress levels and environmental factors such as the poor quality air and water.”

She gives the example of how people living in northern latitudes require higher levels of vitamin D than the RDAs.

Collins mentions recent review studies by the American College of Physicians ( Health + Family , December 31st) that found no benefit from taking food supplements in three large reviews of different population groups.

“I looked further into their review and found that they threw out studies with food supplements using more than the RDAs. If a study shows a benefit, why leave it out?

“There are other multivitamin studies which have found reduction in cancer and increase in survival time with breast cancer.”

Synthetic chemicals
Collins recommends clients take food supplements "because we want to see benefits quickly".

However, she cautions against buying multivitamin supplements made from synthetic chemicals and prefers the natural dried food supplements.

She is adamant that the quality of the supplements make a huge difference to their effect.

Unfortunately, without independent advice, it is extremely difficult for members of the public to tell the difference between a high-quality food supplement and one made from poor-quality synthetic ingredients.

New large-scale publicly funded studies looking at whether high-dose nutritional supplements can maintain or improve the general health of the population are well overdue.

Only then can we become better informed.